Currently, mobile communications systems such as mobile phone systems and wireless MANs (Metropolitan Area Networks) have come into common use. In addition, active discussions on next generation mobile communications technology have been continued in order to further increase the speed and capacity of wireless communication.
For example, the 3GPP (3rd Generation Partnership Project), which is a standards body, has proposed a communication standard called LTE (Long Term Evolution) which allows communication using a frequency band up to 20 MHz (see, for example, 3GPP, “Evolved Universal Terrestrial Radio Access (E-UTRA) Radio Resource Control (RRC); Protocol specification”, 3GPP TS 36.331 V9.0.0, 2009-09). Further, a communication standard called LTE-A (LTE-Advanced) which allows communication using up to five 20-MHz carriers (that is, frequency bands up to 100 MHz) has been proposed as a next generation communication standard after the LTE standard (see, for example, 3GPP, “Feasibility study for Further Advancements for E-UTRA (LTE-Advanced)”, 3GPP TR 36.912 V9.0.0, 2009-09).
Such a next generation mobile communications system is sometimes defined as an extension from its previous generation mobile communications system, rather than being defined as something different from the previous generation mobile communications system. In this case, it may be required that base stations and relay stations complying with the next generation communication standard maintain backward compatibility to accommodate mobile stations complying with the previous generation communication standard. For example, the above-described LTE-A has been proposed as a communication standard extended from LTE. Accordingly, base stations and relay stations complying with LTE-A may be required to accommodate both mobile stations complying with LTE and mobile stations complying with LTE-A.
Note that there is a proposed communication system in which, when a base station transmits an dedicated control signal to terminals under the management of the base station, the dedicated control signal is transmitted using an extended wireless resource region as an dedicated control channel (see, for example, Japanese Laid-open Patent Publication No. 2009-218813). In addition, there is a proposed technique that, in an LTE system, a base station is able to inhibit access from all mobile stations by using Access Barring Information included in a SIB (System Information Block) which is broadcast by a broadcast channel (see, for example, Section 6.3.1 of 3GPP, “Evolved Universal Terrestrial Radio Access (E-UTRA) Radio Resource Control (RRC); Protocol specification”, 3GPP TS 36.331 V9.0.0, 2009-09).
It is sometimes the case that a wireless communication apparatus, such as a base station and a relay station, complying with a next generation communication standard needs to broadcast information not included in broadcast information of a previous generation communication standard to cells under the management of the wireless communication apparatus. For example, while one frequency band (for example, 20 MHz) is used in LTE, multiple frequency bands (for example, 20 MHz×5) may be used in LTE-A. In such a situation, it is conceivable that a base station and a relay station complying with LTE-A need to broadcast information on the multiple frequency bands, which is not broadcast in LTE.
However, it becomes a problem how the wireless communication apparatus capable of accommodating both previous and next generation mobile stations broadcast the information not included in the broadcast information of the previous generation communication standard. Note that the above-described problem regarding the broadcast information is not limited to the case where a wireless communication apparatus accommodates both mobile stations complying with LTE and mobile stations complying with LTE-A, and can possibly occur in general in the case of accommodating multiple types of mobile stations.